We don't know of any time-wise roadmaps, but if you are a brave Linux user, that shouldn't prevent your from building Synfig and having a go at the new features anyway.

By the way, Nikita Kitaev is currently working on SIF exporter for Inkscape which, he hopes, will eventually replace existing SVG importer in Synfig. You can get the Inkscape extension from Github. The discussion is taking place at Synfig's forum.